Rotary deblistering apparatus

ABSTRACT

A rotary deblistering apparatus is described. It comprises a rotatable drum having plurality of circumferential pack holding means each adapted to hold and retain a blister pack. The drum can rotate to locate the pack holding means at a plurality of peripheral work positions including a pack loading position, a pack deblistering position, and a pack detachment position. The blister packs can be loaded onto the drum through a loading means, preferably the loading means has a storage magazine able to supply a continuous number of packs to the drum. For a peelable pack, prior weakening or cutting of the backing of the pack may be necessary or desired. Such action could be carried out at the pack deblistering position. Alternatively, there is a prior weakening and/or cutting position around the drum.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is the U.S. National Phase Application of PCTInternational Application No. PCT/GB99/03618 filed Nov. 02, 1999, andpublished under PCT Article 21(2) in English.

The present invention relates to a rotary deblistering apparatus.

DESCRIPTION OF RELATED ART

Blister packs for pharmaceutical tablets are generally either “pushthrough” packs, where manual pushing of the tablet will eject it fromthe pack through the backing, or “peelable” packs. Peelable packs areintended to be child-resistant, and require the backing to be ‘peeled’away before the tablet is accessible. Deblistering of tablets from apush through pack is generally carried out by passing the packs throughrollers. Because of the more sealed nature of the peelable pack,deblistering of tablets from such packs is often not possible simplythrough rollers, and linear or batch processing has been necessary.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided arotary deblistering apparatus comprising a rotatable drum having aplurality of circumferential pack holding means, each adapted to hold ablister pack, wherein the drum is rotated to locate the pack holdingmeans at a plurality of peripheral work positions including a packloading position, a pack deblistering position, and a pack detachmentposition.

The multiplicity of pack holding means on the drum, and the drum'srotational ability, allow more than one pack to be handled at the sametime, increasing the rate of deblistering of the apparatus compared withprior art static deblistering apparatus. Indeed, the present inventionis able to provide a continuous operation.

The rotational movement of the drum is preferably indexed, and the drumis preferably stationary at each work position.

The drum may have any number of pack holding means, and be of anysuitable size and shape. In one embodiment of the present invention, thedrum has the same or similar number of pack holding means as workpositions around the drum.

Preferably, the drum is vertically arranged. More preferably, the packloading position is located wholly or substantially above the drum, toallow gravity to assist loading of a blister pack onto the drum.Similarly, preferably the pack deblistering position and/or the packdetachment position are located wholly or substantially below the drum,to allow gravity to assist the ejection or detachment of the tabletsand/or deblistered pack from the drum.

The blister packs can be loaded onto the drum through any suitableloading means. The loading means preferably has a storage magazine ableto supply a continuous number of packs to the drum. The loading meanscould also have a pack selection means to assist individual loading ofeach pack onto each pack-holding means. The magazine and/or packselection means is preferably able to deal with curled packs, which areoften the most problematic with prior art deblistering apparatus. Thepack selection means preferably involves opposing means moveable betweenpack-edge support and release positions, generally through reciprocallinear and/or rotational motion. Such means include pins, flanges,discs, etc.

A blister pack can be held by a pack holding means using any suitableattachment means, including vacuum, mechanical fastening aids, and/orpossibly simple friction fit.

The pack holding means are preferably adapted to match the shape, sizeand configuration of the design of the pack to be deblistered. The drumalso preferably allows each pack holding means to be rapidly and easilychanged for different pack designs. The changeability is preferablytool-less, i.e. possible without the need for use of any separate toolssuch as spanners, keys, screwdrivers, etc.

The deblistering of the tablets from a pack held on the drum can becarried out using suitable mechanical or pneumatic force, eg air, pins,etc. Direct force is generally sufficient for deblistering a pushthrough pack. For a peelable pack, prior weakening or cutting of thebacking of the pack may be necessary or desired. Such action could becarried out at the pack deblistering position. Alternatively, there is aprior weakening and/or cutting position around the drum. Such a positioncould be permanently located, but by-passable or inoperable when thepresent invention is being used for push through packs.

The pack holding means may be moveable at one or more the work positionsto effect the operation on the pack thereat. Alternatively, one or moreof the relevant operative means at each work position is moveable whenoperating on the pack held on the drum.

The present invention may be used for any shape, size and design ofblister pack.

According to a second aspect of the present invention, there is provideda method of deblistering one or more blister packs using a rotarydeblistering apparatus as herein described, wherein the pack is loadedonto a pack holding means at the pack loading position, rotated to thepack deblistering position where the tablets are forced out of the pack,and the empty pack is then rotated to the pack detachment position wherethe pack is detached from the pack holding means.

In one embodiment of the method-of the present Invention, the backing ofthe pack is wholly or substantially cut or weakened at a further workposition around the drum.

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

An embodiment of the present invention will now be described by way ofexample only and with reference to the accompanying drawings in which:

FIG. 1 is a front view of a rotary deblistering apparatus according tothe present invention;

FIG. 2 is a side view of the apparatus of FIG. 1;

FIG. 3 is a top view of a first pack plate used in the apparatus of FIG.1;

FIG. 4 is a cross-sectional side view of the pack plate of FIG. 3;

FIGS. 5a and 5 b are plan views of a first pack selection means for usein the apparatus of FIG. 1;

FIGS. 5c and 5 d are side views of the pack selection means in FIGS. 5aand 5 b respectively;

FIGS. 6, 7 and 8 show a top view and first and second cross-sectionalside views of a second pack plate for use in the present invention; and

FIG. 9 is a side cross-sectional view of a second pack selection meansfor use in the apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, FIGS. 1 and 2 show a rotary deblisteringapparatus involving a drum 2 rotatable about a central axle 4. The drum2 has four pack holding means 6 symmetrically located about itscircumference.

Each pack holding means 6 has a pack plate 8 which is shown in moredetail in FIGS. 3 and 4. The plate 8 has a flat top surface 10 and anumber of pockets 12 depending therefrom. The shape, number andconfiguration of the pockets 12 is designed to match the shape, numberand configuration of the blisters on the blister pack or packs to bedeblistered. An aperture 13 extends from the bottom of each pocket 12and through the plate B to a hollow insert 14 in the base of the packplate 8.

Behind each pack holding means 6 is piping (not shown) extending back tointermediate slip plates 20 between the rotating drum 2 and a stationerysupport wall 24. The slip plates 20 are preferably plastic, and may beurged or biased together to maintain an air seal therebetween despitewear.

Using grooves and apertures in the slip plates 20, either an air vacuumor an air over-pressure can be directed through each piping to the baseof each pack plate 8 and then to the pockets 12. One or more bleed orpressure valves may be necessary around the apparatus to ensureequilibrium of pressure or vacuum, or to at least avoid over-pressure orover-vacuum. The pressure or vacuum can be supplied by any suitable pumpmeans known in the art.

The pack plate 8 has, a shoe 16 on each side to match opposing shoulders18 attached to the drum 2 at each pack holding location. Thus, if it isdesired to deblister a pack having a different blister shape, the packplates 8 can be rapidly and easily removed onto and off the drum 2 usinga simple sliding action to fit new plates with the required new pocketshape, etc. A final fastening means could be used to hold each packplate 8 securely on the drum 2. The base of each type of pack plateshould be similar.

The rotational movement of the drum 2 is indexed, such that the drum 2is stationery when the pack-holding means 6 are aligned with thefollowing work positions.

In the apparatus shown in FIGS. 1 and 2, there are four work positions.Uppermost is a pack loading position A. On the right in FIG. 1 is a packcutting position B. Lower most is a pack deblistering position C, and onthe left in FIG. 1 is a pack detachment position D.

The pack loading position A involves a pack loading means 26 with anupright magazine 27 in which a number of blister packs could be stacked,either prior to operation of the drum 2 or continuously. The operationat the base of the pack loading means 26 is shown in more detail inFIGS. 5a-d.

FIGS. 5a-5 d show a pack selection means 26 comprising opposing packedge semi-circular blades 28. The blades a 28 are rotatable about axes29, using reciprocal ram and piston means 30 attached at one corner ofthe blades 28. Each blade 28 has generally arcuate lower and upper frontedges 34, cutaway 31 at different positions around the front edge. Theblades 28 are moveable to move the edges 34 between (lowest) pack-edgeoverlapping positions, shown as “Position 1”, and (lowest) pack-edgeavoiding positions, shown as “Position 2”.

FIG. 5c shows two stacked blister packs 32 a and 32b (generally “32”).The edges of the lowest pack 32 a are held by the lower edges of eachblade 28 above which the upper edges are cutaway. By rotation of theblades 28 from Position 1 to Position 2, the lower edges are drawn awayfrom the pack edges, so as to release lowest pack 32 a to fall bygravity onto an aligned pack holding means 6 therebelow (not shown).Simultaneously, and as shown in FIG. 5d, the offset extended part of theupper edge of each blade 28 is rotated into an overlapping positionunderneath the pack edges of the next blister pack 32 b. Reverse motionof the blades 28 allows the now-lowest pack 32 b to be held by its packedges by the lower extended edges of the blades 28, ready for loadinginto the next pack holding means 6 as it becomes available.

In use, blister packs 32 are fed into the magazine 27 to be loadedaround the drum 2. Vacuum is applied to the pack holding means 6 when atthe pack loading position A to assist loading of a pack 32 onto therelevant pack plate 8. The pockets 12 of the plate 8 accommodate theblisters of the pack 32. The drum 2 is then rotated 90° until the heldpack 32 is aligned with the cutting position B. Where the pack 32 is apush through pack, no cutting may be necessary, such that the pack 32 isnot acted upon at this stage. Where the pack 32 is a peelable pack, acutting tool 36 can be directed against the backing of the pack 32 towholly, or preferably substantially, cut the backing around eachblister.

Meanwhile, a second pack 32 is loaded onto the following pack-holdingmeans 6.

The drum 2 is then rotated 90° again until the first pack 32 is alignedwith the pack deblistering position C. With continuing vacuum applied tothe rear of each pack plate 8 as described above, the pack 32 isretained on the plate 8 even at position C.

At position C, a backing plate 38 is raised against the backing of theheld pack 32. The backing plate 38 has apertures aligned with theblisters of the pack 32 and the pockets 12 of the pack plate 8. With thebacking of the pack 32 thus firmly held between the plates 8, 38, thetablets can be forced out of the pack and collected below position C.The tablets could be pneumatically blown out. The backing plate 38 isthen retracted.

Meanwhile, the following blister pack could be being out at position B,and a third pack loaded at position A.

With further 90° rotation of the drum 2, the empty pack 32 is ready fordetachment at position D. Using a blast or pulse of air through thepiping behind the pack plate 8 instead of vacuum, the empty pack isblown away from the drum 2. The discarded packs could be collected in asuitable bin.

Continuous rotation of the drum 2 clearly allows for continuous loading,optionally cutting, deblistering and detachment of similar blisterpacks.

In one modified arrangement, second pack plates 46 as shown in FIGS. 6,7 and 8 could be used. These pack plates 46 are similar to the firstpack plates 8 described above, in that they have a smooth top surface48, and a number of pockets 50 depending therefrom to suit the shape,number and configuration of the blisters on the blister pack or packs tobe deblistered.

The top plate 52 of the second pack plate 46 fits with a pack holdingmeans, eg the pack holding means 6 in FIG. 1 etc, to form a sealedenclosure, such that again vacuum can be used to retain the blisterpacks on the top plate 52 during the majority of the working cycle ofthe deblistering apparatus. The second pack plates 46 could be held inthe pack holding means by simple catches or bolts etc.

Attached to the top plate 52 via a shoulder bolt 54 is a bottom plate56, biased away from the top plate 52 by two intermediate springs 58.Upstanding from the bottom plate 56 are a series of eject pins 60aligned with the pockets 50. The pins 60 are fixed to the bottom plate56 by holding screws 62.

In use, the second pack plate 46 provides an alternative arrangement forejecting the tablets from a blister pack, especially stronger eg. pushthrough packs. When the blister pack has reached position C as shown inFIG. 1, a backing plate is still brought against the free side of theblister pack to firmly hold it as before. However, a mechanical force,eg. a hydraulic ram or piston, can now be used to impact the base of thebottom plate 56, and force it towards the top plate 52 of the secondpack plate 46. In doing this, the pins 60 will travel up to and throughthe pockets 50, and mechanically push out the tablets from the heldblister pack. A stop bar 64 limits the possible inter-plate distance.

This arrangement provides a usually stronger force of ejection, andpossibly a more even force of ejection across all the pockets 50. Thestrength of each blister is therefore less important. There is also thepotential with the ejection by air pressure that the bursting of any oneblister will effectively nullify or weaken further air pressure action.Use of mechanical pins avoids this.

In a second possible modification to the apparatus, loading means asshown in FIG. 9 could be used. FIG. 9 shows four blister packs 78. Thelowest pack 78 a is held by two sets of lower pins 80 (one of each setis shown). Above these are two sets of upper pins 82, generally held(but not shown) in a retracted position. When the drum 2 has aligned apack holding means 6 below the stack of blister packs 78, the upper pins82 are extended (as shown) to hold the penultimate pack 78 b (and thusall higher packs), whilst the lower pins 80 are retracted to allow thebottom pack 78 a to fall by gravity onto the pack holding means 6. Thelower pins 80 are then re-extended, and the upper pins 82 retracted, toallow the next pack 78 b to be the next loadable pack.

The lower and upper pins 80, 82, like the blades 28 in FIGS. 5a-5 d,have the added advantage that they are able to accommodate curled orotherwise non-flat blister packs by acting on the edges of a pack.

In a third possible modification of the apparatus, the mechanism forloading blister packs onto the apparatus at the pack loading position Acould involve two or more helical screw or augers inclined towards thepack loading position. The substantially vertical screws are locatableon opposite sides of the blister packs, and converge towards the packloading position, such that by rotation, the edges of the packs are metwith the edges of the screws, and then guided downwards towards the packloading position A. With the slight downward convergence of the screws,once the edges of the blister packs are located within the grooves ofthe screws, they will be continuously guided downwards towards the packloading position A. The use of such screws may provide better andsmoother catching of the edges of blister packs, and result in lessrejection of misshaped blister packs, ie packs which may be curled orotherwise non-flat. The rotating screws also provide a continuousmechanism for regularly downloading the blister packs into the packloading position A, without requiring separate or discrete pack loadingoperations.

The apparatus of the present invention as shown in FIG. 1 can be locatedwith a box or cover 40, which could also be wholly or substantiallysealed to minimize the possibility of contamination during thedeblistering operation. FIG. 2 also shows the apparatus located on amobile platform 42, making it easily relocatable. The motors and valvesfor the vacuum to the drum 2 and for the pneumatics for the operablework stations are located in a rear cabinet 44.

It is considered that the present invention could deblister fifty ormore average peelable blister packs per minute, compared with the commonmaximum of twenty peelable packs per minute with batch or individualisedprior art apparatus. The present invention can also deal with curledpacks, which often block or jam prior art apparatus.

The present invention furthermore has the ability for tool-less changingof its plates to fit different sized, shaped or configured blisterpacks. Thus, the number of each type of pack to be deblistered, whetherit be one or a thousand or more, makes little difference to the timerequired for deblistering.

The present invention also avoids the use of belts or chains to conveythe blister packs between the work positions, decreasing the possibilityof any contamination of the tablets from oil or grease etc.

We claim:
 1. A rotary apparatus for deblistering a pharmaceuticalblister pack having a number of product blisters, and having asubstantially flat face, the apparatus comprising: a rotatable drumhaving a plurality of circumferential pack holding means, each packholding means having complementary pockets corresponding to the blistersof the blister pack, at least one aperture therethrough, and means todeblister the product from the pack; a vacuum means to provide a vacuumpressure through the at least one aperture to positively position andhold steady the blister pack onto the pack holding means; a pack loadingmeans wholly or substantially above the drum to load the blister packwith the blisters face down onto the pack holding means; and means torotate the drum to locate the pack holding means at a plurality ofperipheral work positions including a pack loading position, a packdeblistering position, and a pack detachment position.
 2. Apparatus asclaimed in claim 1 wherein the rotational movement of the drum isindexed.
 3. Apparatus as claimed in claim 1 wherein the drum isstationary at each work position.
 4. Apparatus as claimed in claim 1wherein the drum has the same number of pack holding means as workpositions around the drum.
 5. Apparatus as claimed in claim 1 whereinthe drum is arranged to rotate about a horizontal axis.
 6. Apparatus asclaimed in claim 1 wherein at least one of the positions selected fromthe group consisting of the pack deblistering position and the packdetachment position is located wholly or substantially below the drum.7. Apparatus as claimed in claim 1 wherein the pack loading means has astorage magazine able to supply a number of packs to the drum. 8.Apparatus as claimed in claim 1 wherein the loading means has a packselection means to provide individual loading of each pack onto eachpack-holding means.
 9. Apparatus as claimed in claim 8 wherein the packselection means comprises two opposing means moveable between pack-edgesupport positions and pack-edge release positions.
 10. Apparatus asclaimed in claim 1 wherein the pack holding means are adapted to matchthe shape, size and configuration of the design of the pack to bedeblistered.
 11. Apparatus as claimed in claim 1 wherein each packholding means is changeable.
 12. Apparatus as claimed in claim 1 whereinthe pack deblistering position includes a force selected from the groupconsisting of mechanical, pneumatic, and combinations thereof, todeblister tablets from a pack held on the drum.
 13. Apparatus as claimedin claim 1 wherein at least one of the positions selected from the groupconsisting of a pack weakening position and a pack cutting peripheralwork position, is located before the pack deblistering position. 14.Apparatus as claimed in claim 1 wherein the pack holding means ismoveable at one or more of the work positions.
 15. Apparatus as claimedin claim 1 wherein at least a portion of the apparatus at one or more ofthe work positions is moveable when operating on a pack held on thedrum.
 16. A method of deblistering one or more blister packs using arotary deblistering apparatus as claimed in any one of claims 1 to 15,wherein the pack is loaded onto a pack holding means at the pack loadingposition, rotated to the pack deblistering position where the tabletsare forced out of the pack, and the empty pack is then rotated to thepack detachment position where the pack is detached from the packholding means.
 17. A method as claimed in claim 16 wherein the packincludes a backing and the backing of the pack is wholly orsubstantially cut or weakened at a further work position around thedrum.
 18. A method as claimed in claim 16 wherein deblistering of thetablets from a pack held on the drum is carried out using force selectedfrom the group consisting of mechanical, pneumatic, and combinationsthereof.